Rolling mil assembly

ABSTRACT

A ROLLING MILL WITH FREESTANDING UPPER AND LOWER SUPPORT ROLLERS CLAMPING A PAIR OF WORKING ROLLS BETWEEN THEM UNDER PRESTRESS ARISING FROM TENSIONING RODS SPANNING UPPER AND LOWER BEAMS OF THE MILL STRUCTURE SO THAT THE ROLLING PRESSURE ACTS COUNTER TO THE PRESTRESS AND RELIEVES ECCENTRICS DISPOSED BETWEEN THE UPRIGHTS AND THE UPPER BEAM FOR ADJUSTMENT OF THE ROLLING GAP.

United States Patent lnventor Robert Kracht [56] References Cited Essen. Germany UNITED STATES PATENTS 9521' g: '2 1968 3,124,982 3/1964 Neumann 72/21 pzmmed g 1971 3,355,925 12/1967 Bamikel et a1... 72/244 Assignee Fried Krupp Gmbfl Essen Germany 3,381,511 5/1968 Canfor etal. 72/248 Priority May 30, 1967 131,224,679 3/1962 Fox 72/243 Germany 86,501 11/1966 Tracy 72/237 P 16 02 030.7 Primary ExaminerCharles W. Lanham Assistant Exuminer B, J. Mustaikis Attorney--Karl F. Ross 3" EM ABSTRACT: A rolling mill with freestanding upper and lower support rollers clamping a pair of working rolls between them U.S. Cl 72/237 under prestress arising from tensioning rods spanning upper Int. Cl B2lb 31/04, and lower beams of the mill structure so that the rolling pres- B2lb 31/24 sure acts counter to the prestress and relieves eccentrics Field of Search 72/237.l, disposed between the uprights and the upper beam for adjust- 237, 243, 245, 246, 248, 240, 21 ment of the rolling gap.

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PATENTEDJUNZBIQYI $587,278

' saw 1 ur 2 i In van or: L n Robert Krachf By A 5 00 Attorney My present invention relates to rolling-mill assemblies and. more particularly, to a roll arrangement for a rolling mill in which the rolls are freestanding, i.e. are not fixedly journaled upon any rigid support frame or structure. I

The use of support stands or frames to carry the working rolls of a rolling mill for the hot or cold rolling of metal stock is acommon practice in the field and it has also been proposed to provide freestanding roll arrangements in which the journal portions of the working rolls are not lixedlymounted upon a stand but are retained between upper and lower traverses or beams which retain the vertically shiftable journal blocks in place. Spindles or hydraulic-cylinder arrangements may adjust the gaps between the working rolls (see the journal "Black," 1966, No. 2, pages 52-57). Difficulties have, however, been encountered in setting the working gap and maintaining any necessary prestress upon the working rolls.

It is, therefore, the principal object of the present invention to provide an improved rolling-mill assembly wherein these disadvantages are avoided.

l have now found that it is possible to eliminate the disadvantages of earlier systems and yet provide a freestanding rolling-mill assembly which can be prestressed and accurately adjusted with respect to the working gap when the assembly comprises upper and lower support rollers or rolls of conventional construction which bear against or osculate the upper and lower working rolls of smaller diameter'which are driven by conventional means and advantageously have their axes lying in a common vertical plane with the support or stressing rolls.

In accordance with the principles of the freestanding rolling mill with which the present invention is concerned, the rolls and rollers have respective journal blocks which are posiv.tioned one above the other'between a pair of uprights on each side of the rolls array so as to be free to move in the vertical direction and to allow the support rollers to bear against the working rolls in opposition to the rolling pressure generated when the workpiece is passed between the latter.

An upper beam, according to the present invention, bears against the journal blocks or insert pieces in which the upper support roller is rotatably mounted and is held thereagainst by adjustable tensioning means spanning the upper and lower beams. Adjusting means is'provided, in accordance with my present invention, between the uprights (which do not directly support the roller or roll bearings) and the upper beam to establish the fine adjustment of the working roll gap during the course of the rolling process, while a threaded-spindle arrangement is carried by the upper beam to provide a coarse adjustment of the gap. The fine adjusting means, comprising roller-bearing-journaled eccentrics, generates a force parallel to the prestress applied in the vertical direction to the supporting rollers and operates directly upon the upper beam thereby allowing a rapid and precise adjustment of the rolling gap.

An advantage arises in that the adjusting device, during the rolling stage or operation is relieved from the pretension force .(which is countered by the oppositelyacting roller force) so thatthe eccentric arrangement need only sustain the proportionately small pressure difference between the pretension and counteracting rolling forces. The system thus makes it possible without more to compensate for variations in the rolled-goods thickness, wear of the rollers, etc. The hydraulic systems for the pretension and the fine adjusting means can be FIG. 3 is a detail view illustrating an eccentric adjusting arrangement in cross section for use in the device of FIGS. 1 and 2 From FIGS. 1 and 2 of the drawing, it can be seen that the upper support head I is a traverse provided with a pair of transversely extending yoke portions la and lb connected by the crossbeam It. supporting a hydraulic motor ll whose function will be set forth in greater detail hereinafter. At the center of each of the yoke portions la and lb, a respective vertical spindle i2 is rotatably mounted. This spindle l2 has a splined portion 120 rotatably engaged by a worm wheel l2b whose worm lie is driven by the hydraulic motor 11 via an overloading clutch lib and a speed-reducing transmission lie. The threaded portion lie of the spindle I2 is received in a nut la anchored in the yoke portion as shown for the yoke portion lain FIG. I.

At its end extending below the upper support beam 1, each spindle 12 carries a head 12d rotatable relatively to the spindle and provided with a thrust-bearing structure 12c effective in the vertical direction to urge a pair of journal blocks 9 upwardly or downwardly with respect to the upper beam 1.

The journal blocks 9 are vertically shiftable between pairs of uprights 14a and 146 each constituting nonsupporting stands flanking the journal blocks 9 and guiding them for vertical movement between the flanks 14a and 14b. From the journal blocks 9, secondary journal blocks 16 are suspended by yieldable connecting member 17, the journal block 16 rotatably supporting the shafts 7' of the upper working roll 7 of the mill. The lower working roll 8 has its shafts 8 joumaled in the vertically shil'table U-shaped blocks 18 each of which receives the block 16 (FIG. 2) and is vertically guided between the flanks 14a and 14b of the uprights 14a and 14b without being supported thereby.

Each of the uprights 14a, 14b is'mounted upon a respective lower crossbeam 3a or 36; the latter, in analogy to the upper beam I, extend transverse to the working rolls 7 and 8 and are connected by a transverse portion 30 in the form of l-beams supporting rails 3 4. These rails, in turn, are rollingly engaged by the journal blocks 10 of the lower prestressing roll 6. The journal blocks 10 have wheels 10a 'rollingly'engaging the rails M to allow at least limited longitudinal movement of the array of rolls therealong.

It is thus evident'that' the upper transverse yokes la or lb of the upper support beam 1 on each side' of the vertical array of rolls 5, 7, 8, 6 are drawn toward the lower transverse members 3d and M0! the pedestal or support member 3 by pairs of ten operated by sensors or the like responsive to the thickness of the goods to be rolled in the usual manner. I

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a vertical elevational view, partly in section, along the line H of FIG. 2 of a rolling mill seen in the rolling" direction in accordance with the present invention;

FIG. 2 is a side elevational view, partly in section, along the line ll-ll of FIG. 1 and partly broken away; and I sion rods 2 exerting the desiredradial prestress upon the roll array. As can be seen in FIG. 2, each of the tension rods 2 extends upwardly through a lateral lug 1c of the respective yoke portion 14 beyond a horizontal shoulder 1] against which the rod 2 is anchored by a nut 2a. The rods 2 pass through sliding bearings [4c in substantially upright passages 14d in which the rods are received with limited lateral clearance, the passages 14d being formed in relatively massive blocks 14 at the upper end of each of the uprights 14. The uprights 14a may be fonned of steel profiles whose webs 14f are perforated to clear the rods 2 which terminate in pistons 2b slidably received in hydraulic cylinders 4 swingably mounted by their lugs 40 and pins 4b upon the support member or pedestal or support members 3. The uprights 14a and 14b are affixed by bolts to the pedestals.

The piston-and-cylinder arrangement 2b. 4 applies the desired vertical prestress to the supporting rolls 5 and 6 which, in turn, clamp the working rolls 7 and 8 between them so that the support rolls 6 and 7 are stressed between theupper and lower beams 1 and 3. When metal goods are rolled, the rolling pressure counteracts the prestress and relieves pressure on the adjustingdevices 13. I

Between the upper bearing blocks 9 and the upper beam 1 are the adjusting spindles 12 which permit coarse adjustment vertically displaced (arrow A) to lift or lower-the journal blocks 9 engaged by these spindles via thrust bearing assemblies l2d and De.

For fine adjustment of the rolling gap during the rolling process, adjusting devices 13 are provided at each of the blocks 14 as mentioned earlier. The adjusting device carried by each of the posts comprises a roller-bearing supported eccentric adapted to generate under the control of hydraulic fluid a lifting movement at the upper beam 1 as represented by the arrows B. To this end each adjusting device 13 is provided with a hydraulic motor 130 (all of which may be energized in parallel) for driving via speed-reducing gearing (if necessary) the shaft 13b of an eccentric 13c which, via a roller bearing array 13d acts upon the force-transmitting member or body 13 (received between the beam member and the eccentric) whose upper end 13f is a spherical sector received in a correspondingly shaped seat 133 in the upper beam 1.

The improvement described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the invention except as limited by the appended claims.

lclaim:

l. A rolling mill comprising:

a support member;

a beam member spaced above said support member;

a pair of vertically juxtaposed working rolls between said support member and said beam member;

a pair of vertically spaced support rolls sandwiching said working rolls between them, said rolls resting upon said support member;

prestressing means including a contractile hydraulic cylinder arrangement including a hydraulic cylinder connected to one of said members and a piston connected to the other of said members and slidable in said cylinder, said cylinder being hydraulically pressurized for yieldably drawing said members toward one another under substantially constant predetermined pressure, the upper support rolls bearing upon said beam;

rigid fine adjustment means between said support member and said beam member for adjustably holding same apart at a predetermined minimum spacing.

2. The rolling mill defined in claim I, wherein said rigid fine adjustment means includes a body bearing against said beam member and an eccentric disposed between said body and said support member.

3. The rolling mill defined in claim 2 wherein said support member includes a support beam and a pair of uprights spaced apart along said beam and vertically guiding said rolls at opposite ends thereof, at least one such prestressing means being provided at each of said uprights, said mill further comprising coarse adjustment means on said beam member engageable with said upper support rolls for holding said upper support rolls and said beam member at a minimum predetermined spacing, the cylinders of said prestressing means being provided on said support beam, the pistons of said prestressing means having piston rods anchored to said beam member.

4. The rolling mill defined in claim 3 wherein said coarse adjustment means includes a respective vertically threaded spindle rotatably mounted on said upper beam member at each end thereof and bearing upon the corresponding end of said upper support roll, mechanism for rotating said spindles, respective nuts on said beam member threadedly engaging said spindles for vertical movement thereof upon spindle rotation, and means coupling each of said spindles with said upper rolls and including a thrust-bearing assembly.

5. The rolling mill defined in claim 4 wherein said mechanism comprises a respective worm wheel rotatably entraining each of said spindles. and a hydraulic motor for driving said worm wheel, each of said spindles having a splined portion received in the respective worm wheel with freedom of axial movement relative thereto, said beam member having a pair of yoke portions at opposite ends of said rolls and extendin transversely thereof, each of said yoke portions bein provi ed at a central location with a respective one of sand spindles and at each extremity of each of said yoke portions with a respective one of said rods and a respective one of said rigid fine adjusting means.

6. The rolling mill defined in claim 5 further comprising a roller bearing between said eccentric and said body. 

